1. Field of the Invention
The invention relates generally to preservation of meats under ambient consumer conditions and somewhat more particularly to a process of producing dry sausages as well as the resultant sausage products.
2. Prior Art
Sausages of various types are well known in the art from antiquity. In the earliest recorded histories of civilization, references are found to production of various sausages. "Sausage" apparently is derived from the Latin term "salsur", a term designating a common method of preserving foods, particularly meats by salting. Sausage makers empirically determined that certain admixtures of spices, salts and meats, when subjected to certain procedures, produced a sausage that did not spoil when stored in ambient or warm environment. Treatment of a meat mass by the addition of salt, nitrates and nitrites as well as by smoking the so-treated meat mass in dense smoke resulted in varying degrees of product safety and stability.
As described by Kramlich, Pearson and Tauber in PROCESSED MEATS, "Dry Sausage", page 136 (Avi Publishing Co., 1973):
"semidry sausages are smoked and cooked to varying degrees, whereas dry sausages are not cooked and only with some products is smoke applied. The manufacture of dry sausage is more difficult to control than that of semidry or more conventional type sausages. Overall processing time may require 90 days. As a result of this prolonged holding, the sausage is vulnerable to chemical and microbiological degradation. However, when prepared properly, the finished sausages are usually stable and can be held with little or no refrigeration. The salt, acid and moisture content, as well as the specific types of organisms associated with the product, make for the characteristic flavor and texture of dry sausages. The raw materials and the sequence of events must be carefully controlled. Dry sausages are the `ne plus ultra` of the industry and the dry sausage maker is truly an artist."
In relatively recent times, sausage makers discovered that refrigerated storage of a meat mass in containers which permit substantial exposure to air (such as pans, trays, etc.) allowed fermentation of the meats mass by growth of acid-producing bacteria, primarily lactobacilli. Such bacteria growth produced lactic acid in the meat mass, which is beneficial because it inhibits the growth of certain pathogenic bacteria. Such inhibitory action appears to be primarily due to the rapid consumption by the lactobacilli bacteria of the glucoses naturally present in meats, thereby denying a readily-available food supply to other bacteria. Additionally, the acid produced by the lactobacilli yields an environment which inhibits or prevents growth of certain other bacteria which are also indigenous to meats and may be highly toxic to man and certain animal species by the production of toxins (particularly the toxin of clostridium botulinum). Subsequent to this fermentation of a meat mass (which typically takes 2 to 4 days), and forming stuffed sausages therefrom (which may be suspended in a smoke house, depending on the preference of the customer or consumer), the sausages were dried by hanging in a relatively cool, ventilated room for long periods of time until a substantial portion of the moisture in the meat mass migrated from the interior of such sausage to the surface of the casing and evaporated by circulating air currents. This process required a relatively long time period (up to about 120 days) to yield a useful product and to insure slow, even drying and shrinkage. Attempts to dry such sausages more rapidly typically resulted in the formation of a "skin" of dried meat on the outer portions of the sausages which entrapped the moisture in the center or interior of the sausages, thereby permitting bacterial and enzymatic spoilage to occur within such sausages. Disadvantages of currently known methods of producing dry sausage include one or more of the following aspects:
1. Traditional dry sausage production processes provide significant risk of deterioration of the sausage product by bacterial or enzymatic activity during the long processing and drying periods required.
2. Traditional dry sausage production processes involve high labor costs due to the numerous times that the meat mass must be handled prior to placement in a drying room.
3. Traditional dry sausage production processes include a hazard of unpredictable loss by spoilage of the finished sausage product due to the growth of undesirable organisms.
4. Traditional dry sausage production processes frequently cause the development of undesirable flavors in the meat mass due to excessive production of lactic acid by lactobacilli bacteria that are indigenous to fresh meats which are fermented during the time periods and in the temperature ranges prescribed in the prior art (storage for 2 to 10 days at about 4.degree. C. to 7.degree. C.).
5. Traditional dry sausage production techniques frequently cause the development of undesirable flavors in the meat mass induced by the addition of a bacteria culture to such meat mass prior to stuffing the meat mass into natural or artificial casings.
6. Traditional dry sausage processing techniques require large investments of capital in order to build drying rooms of sufficient size to store sausage products for the presently required drying time periods (up to 120 days).
7. Traditional dry sausage production techniques require a large commitment of capital in order to finance inventories of sausage products during the total processing and drying periods typically required.
Sair U.S. Pat. No. 2,992,116 suggests that the bright red color and permanence thereof in fresh or cured meat emulsions may be improved without adverse effects on the water-binding capacity and the emulsifying qualities of meat proteins by adding relatively small, precise amounts of glucono delta lactone to meats as they are undergoing emulsification. However this publication does not relate to dry sausage production.
In addition, certain prior art publications, such as Marchand U.S. Pat. No. 1,167,193; Gooding U.S. Pat. No. 2,379,294; Coleman et al U.S. Pat. No. 2,474,228; Douglass et al U.S. Pat. No. 2,901,354 and others suggest adding various chemical acidulants to meat masses for various purposes, including producing hostile environments for common pathogens. However, such prior art processes are generally unsatisfactory because the wide variation in raw material acid content, unanticipated contaminations of raw materials and equipment, as well as improper hygiene of workers, all contribute to product failure, and are unsatisfactory for commercially reliable sausage-making processes. Further, certain prior art publications, such as Nickerson et al U.S. Pat. No. 3,899,594, suggest incorporating a select bacteria culture along with certain acidulants into various food stuffs to prolong the storage life thereof. However, such processes yield undependable results because bacteria conditions in raw materials, equipment and workers is not sufficiently known (or controlled) in commercial processes.
In my prior U.S. Pat. No. 3,664,850 I describe and claim a novel method for fast drying of meat masses in casings. Generally, such process comprises applying positive liquid-expressing pressure to casing-bound meats so as to force moisture therefrom and rapidly removing the so-expressed moisture by relatively high temperatures and low relative humidity conditions. However, that process is materially distinct from the present invention.
In addition, Piret et al U.S. Pat. No. 2,346,232 and Christianson et al U.S. Pat. No. 3,482,996 suggest other processes for relatively quickly dehydrating meat masses, either by spreading a comminuted meat mass in a thin layer and forcing high velocity relatively dry air across such meat mass to dry such meats or by admixing dehydrated protein fibers with the meat mass to attain a lower average moisture content within the resultant mixture. However, neither of these processes are suitable for dry sausage production.
Some of the most significant deficiencies of the earlier-described traditional methods of producing dry sausages generally comprise (1) the "art" aspect of the overall process, which makes mass production and standardization of product difficult; (2) the considerable risk of product spoilage throughout the prolonged manufacturing process; (3) the significant danger of economic loss by recall of a product lot, if determined to contain various pathogens; (4) the high costs of facilities and inventories necessary to maintain a viable commercial enterprise; and (5) the frequently encountered undesirable molds on sausages in the drying room, induced by relatively low temperatures, high humidity and extended drying time periods typically required.